JP6399352B2 - Methods for separating and recovering platinum group elements - Google Patents

Description

  The present invention relates to a method for separating and recovering platinum group metals (PGM), and more particularly, from a chloride solution containing a platinum group element at a relatively low concentration and a high concentration of impurity elements, from a chloro complex. The present invention relates to a platinum group element separation / recovery method in which platinum group elements in the form of chlorides, etc. are selectively adsorbed and eluted using a synthetic resin containing an amine to separate and recover the contained platinum group elements.

Platinum group elements are rare elements in terms of resources, and are rarely produced as ores containing only platinum group elements containing high quality platinum group elements. In addition, industrially produced platinum group elements are produced by refining and separating by-products in the smelting process of these non-ferrous metals that are incidental to ores such as copper, nickel and cobalt. Is.
In addition, the ratio of platinum group elements recycled from various used waste catalysts such as automobile exhaust gas treatment catalysts is also high.

  Among these, when recovering platinum group elements as by-products from non-ferrous metal smelting, platinum group elements such as platinum, palladium, iridium, rhodium, ruthenium, and osmium contained in trace amounts in the smelting raw materials However, due to its chemical properties, it is concentrated in the main metals such as copper and nickel sulfide concentrates and crude metals, and further concentrated in the process of recovering the main metals such as selective leaching and electrolytic purification, and finally A noble metal concentrate containing a platinum group element as a residue or the like is separated.

  The separated noble metal concentrate includes main metals such as copper and nickel, as well as other constituent elements such as gold and silver, group 16 (former name: group VI) elements such as selenium and tellurium, bismuth and antimony. In general, a group 15 (former name: group V) element such as arsenic coexists with a higher content than a platinum group element. After that, the platinum group element is recovered through recovery of gold and silver, but usually a method of leaching into the liquid and then purifying and recovering by solvent extraction, ion exchange method, etc. is performed. .

  By the way, since the platinum group element concentration in the aqueous solution containing the platinum group element is usually very low, the ion exchange method is particularly suitable for primary concentration rather than solvent extraction. In addition, platinum group elements are usually handled by being dissolved in an aqueous chloride solution, and in the aqueous chloride solution, the platinum group element exists as an anion of a chloro complex. Therefore, it can be adsorbed and collected by a resin or adsorbent having anion exchange ability.

A commercially available anion exchange resin has a rigid structure in which an amino group or a quaternary ammonium group is directly bonded to a carbon atom of a basic skeleton based on styrene or acrylic of the resin.
Therefore, a platinum group chloro complex (for example, [MCl ₆ ] ²⁻ ) which is an anion is adsorbed by exchanging it with an anion constituting an amine salt or a quaternary ammonium salt in the resin.
However, the adsorption power is weak only by simple anion exchange, and in fact, the adsorption power is increased by a so-called chelate effect that wraps a metal ion with a plurality of amino groups attached to adjacent carbon atoms.

A polyamine type anion exchange resin, which is a kind of anion exchange resin and has multiple amino groups as functional groups, has a high chelating effect due to its high density of amino groups, and has a stronger complexing ability than ordinary anion exchange resins. Have.
An anion exchange resin having a primary to tertiary amine as a functional group corresponds to a weakly basic resin, and thus a weak acid type platinum group chloro complex (for example, [M (H ₂ O) ₂ Cl ₄ ] ⁻ etc. ) Can be adsorbed. On the other hand, it is difficult to adsorb many metal ions such as copper, whose anions are unstable, or arsenic, hexavalent selenium ions, hexavalent tellurium ions, etc. that form strong acid oxoacid ions in chloride solutions have.
Therefore, using this chemical property, the anion exchange resin can selectively adsorb only the platinum group element in the presence of the impurity element.

Many methods are known as a method for adsorbing a platinum group element from an aqueous solution containing a platinum group element using the anion exchange resin, and typical examples include the following examples.
In Patent Document 1, platinum that has been adsorbed by bringing an aqueous solution containing a platinum group element into contact with an adsorbent in which thiourea, urea, amine, or polyamine is bonded to polyolefin, fluorinated polyethylene, cellulose, or viscose by radiation grafting is disclosed. A method for eluting group elements with strong acids, salts and complexing agents is described.

In Patent Document 2, in a method for recovering a platinum group element from a chloride solution containing a platinum group element and an impurity element, the platinum group element is selectively adsorbed by contacting the chloride solution with a polyamine type anion exchange resin, A method is described in which the resin after the adsorption treatment is washed with dilute hydrochloric acid and water, and then the platinum group element is eluted from the resin after the washing treatment with thiourea and, if necessary, hydrochloric acid.
In the method of Patent Document 2, with respect to elution, thiourea, which is an optimal eluent, is used, and further, elution is performed at a high temperature of 60 to 90 ° C. to thereby remove a platinum group element that is easily fixed by the chelate effect in the resin. Although iridium, ruthenium, and rhodium can be effectively eluted and iridium, ruthenium, and rhodium, which are considered to be particularly difficult to elute by additional elution with thiourea followed by hydrochloric acid, are shown, iridium There was room for further improvement in the elution rates of the three elements, ruthenium and rhodium.

Patent Document 3 describes a platinum group element recovery method using a resin alloyed with a polymer containing an amino group and a polymer alloy, which has a more flexible structure than conventional anion exchange resins and exchangers. Has been.
The method disclosed in Patent Document 3 is excellent in that the elution reaction of a platinum group element or a coexisting element chloro complex once strongly adsorbed easily proceeds. However, in order to obtain a polymer alloy having physical and chemical stability that can withstand practical use, the amount of amine contained in a certain volume of resin must be limited. Adsorption capacity is limited.
In addition, since it is produced by physically mixing a polymer containing an amine with another polymer, the amine in the resin is reduced with use, and the adsorption capacity of the platinum group element may be reduced.

Japanese Patent No. 4198460 Japanese Patent No. 4144411 JP 2014-181393 A

  An object of the present invention is to solve the above-mentioned problems of the prior art, and to achieve high selectivity and adsorption rate with a platinum group element in a chloride aqueous solution in the presence of a high concentration of impurity elements, and a conventional resin. An object of the present invention is to provide a physically and chemically stable method for adsorbing platinum group elements with a higher adsorption capacity and eluting the adsorbed platinum group elements at a high elution rate.

  As a result of intensive studies to solve the above problems, the present inventors chemically bonded a polymer containing an amino group and a hydrophilic polymer to a chloride solution containing a platinum group element at a relatively low concentration. When a water-insoluble resin having a structure is applied to the adsorbent, platinum group elements can be adsorbed selectively and with a high adsorption capacity, despite the presence of high-concentration impurity elements in the chloride solution. The present inventors have found that the elution rate is significantly improved as compared with conventional anion exchange resins and that the method is physically and chemically stable, and the present invention has been completed.

That is, the first invention of the present invention, there is provided a method of recovering the platinum group elements from acidic solutions containing at least platinum or ruthenium platinum group element and impurity elements, the following steps (1) to (3) in order undergoes that the This is a method for separating and recovering platinum group elements.

(1) Adsorption treatment in which the acidic solution is brought into contact with water-insoluble resin having a structure in which an amino group-containing polymer is chemically bonded to a hydrophilic polymer, and the platinum group element contained in the acidic solution is adsorbed on the resin. The first step to do.
(2) A second step of cleaning the resin that has adsorbed the platinum group element through the first step.
(3) A third step in which an aqueous solution containing thiourea having a liquid temperature of 60 to 90 ° C. is brought into contact with the resin having undergone the second step, and the platinum group element adsorbed on the resin is eluted.

  In the second invention of the present invention, the acidic solution in the first step of the first invention is maintained at a potential of 700 to 1100 mV as a redox potential using a silver / silver chloride electrode as a reference (reference) electrode. This is a method for separating and recovering platinum group elements.

  In the third invention of the present invention, in the first and second inventions, the washing process in the second step is to wash the resin after the adsorption treatment by sequentially bringing the hydrochloric acid solution and water into contact with the resin after the adsorption treatment. This is a method for separating and recovering a platinum group element, characterized by being a treatment.

  A fourth invention of the present invention is a method for separating and recovering platinum group elements, wherein the chlorine ion concentration of the hydrochloric acid solution in the third invention is less than 4 mol / L.

  In the fifth invention of the present invention, after the elution treatment in the third step of the first to fourth inventions, after bringing the resin after washing treatment into contact with an aqueous solution containing thiourea, the concentration is 2 mol / L or more. This is a method for separating and recovering a platinum group element, wherein the hydrochloric acid is brought into contact with the resin.

Sixth aspect of the present invention, the acidic solution in the fifth invention of the first is at least one platinum group elements platinum, selected from the group consisting of Le ruthenium, copper, nickel, gold, silver, selenium, A platinum group element separation / recovery method comprising an acidic or chloride solution containing hydrochloric acid containing at least one impurity element selected from tellurium, bismuth, antimony, and arsenic.

  According to the present invention, water having a structure in which a polymer containing an amino group and a hydrophilic polymer are chemically bonded from a chloride solution containing a platinum group element at a relatively low concentration and coexisting with an impurity element at a high concentration. Using an insoluble resin, it is physically and chemically stable to adsorb platinum group elements existing in the form of chlorides such as chloro complexes selectively and with a high capacity and to elute with a high elution rate. Therefore, its industrial value is extremely large.

FIG. 3 is a graph showing Pt adsorption isotherms of adsorbents (I to III) in Example 1. It is a figure which shows transition of Pt distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Pd distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Ir distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Ru distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Rh distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Au distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Pb distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Sb distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of As distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Sn distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Te distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Bi distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Se distribution rate [%] for every cycle in Example 2. FIG. It is a figure which shows transition of Cu distribution rate [%] for every cycle in Example 2. FIG.

  Hereinafter, the platinum group element recovery method of the present invention, particularly each step of resin selection, adsorption, washing, elution, and platinum group element recovery will be described in detail.

(1) Adsorbent of platinum group element The adsorbent used in the present invention is a resin insoluble in water (hereinafter referred to as “adsorbent I: amine-containing hydrophilic” having a structure in which a polymer containing an amino group is chemically bonded to a hydrophilic polymer. ”Resin or simply“ resin ”), a polymer containing an amino group is chemically bonded to the base hydrophilic polymer. Compared to conventional ion exchange resins, ion diffusivity inside the resin And the amine in the resin is less likely to decrease.

  At the time of adsorption, like conventional anion exchange resin, especially polyamine type resin, it forms a strong bond with metal chloro complex temporarily due to chelate effect, and the high selectivity to impurities is similar, but elution In some cases, due to the high ion diffusibility in the resin, the once adsorbed chloro complex is rapidly released out of the resin particles, and as a result, the elution rate is considered to increase.

The ion diffusivity inside the resin is considered to increase as the hydrophilicity of the polymer as a base increases. However, if the hydrophilicity is too strong, the solubility of the base itself in acid and water increases and the life of the resin itself is shortened. Therefore, it is important that the matrix does not dissolve in water or acid.
The amine which is a functional group has a polymer containing the amine chemically bonded to the base polymer. By being chemically bonded, the resin is provided with physical and chemical stability, so that it is not necessary to limit the adsorption capacity of the resin. In addition, the amine in the resin is difficult to decrease due to the chemical bond.

  An amine-containing hydrophilic resin satisfying such properties can be produced by using a known method described in, for example, Japanese Patent Application Laid-Open No. 2014-111732. The base polymer is not particularly limited as long as it is hydrophilic, and a known polymer having a hetero atom such as cellulose, acrylic acid, or sulfonic acid can be used.

(2) First step (adsorption step)
The first step (adsorption step) of the present invention is a step of selectively adsorbing a platinum group element from a chloride solution containing the platinum group element using the amine-containing hydrophilic resin of (1). . This adsorption step can be performed by a known column type or batch type.

In the adsorption step, the oxidation-reduction potential (ORP) of the chloride solution containing a platinum group element is preferably in the range of 700 to 1100 mV, more preferably as the potential when a silver-silver chloride electrode is used as the reference electrode. 800 to 1000 mV, more preferably 850 to 970 mV.
That is, since a platinum group element is most likely to form a chloroanion complex with a tetravalent ion, it is preferably 700 mV or more, at which the main platinum group element ion is tetravalent, and if it exceeds 1100 mV, the resin is oxidized and deteriorated. This is because of concern.

  The oxidation-reduction potential of the chloride solution is adjusted by adding an oxidizing agent to the processing stock solution at a stage before the adsorption step. In addition, when performing the adsorption operation by continuously passing the stock solution through the resin-filled column, if the potential of the effluent from the column decreases due to the adsorbed reducing substance, etc., the potential of the processing stock solution is again measured. It is preferable to improve the adsorption rate by raising the liquid to the above range. In addition, the oxidation-reduction potential in the present invention is expressed as a potential when a silver / silver chloride electrode is used as a reference (reference) electrode.

  Further, the treatment temperature in the adsorption step is not particularly limited, but it is preferably carried out in the range of 90 ° C. or less from the industrially realized room temperature to prevent deterioration of the resin.

(3) Second step (cleaning step)
The washing step of the second step of the present invention is a step of washing the amine-containing hydrophilic resin after the adsorption treatment in the first step (adsorption step) using a washing liquid.

The resin after adsorption treatment hardly adsorbs cations such as copper ions and strong acid type anions such as selenium and tellurium oxoacid ions, but the solution is physically impregnated inside the resin and contains impurity components. ing.
Therefore, a high-quality platinum group element solution is recovered as an eluent in the second step, and in order to prevent side reactions from proceeding by mixing the adsorbed solution and the eluent, an ion exchange resin is used before elution. It is necessary to remove the impregnating solution physically contained by washing.

  Water can be used as the solution used for cleaning (cleaning solution), but when there are elements that are easily hydrolyzed in the coexisting impurity elements, it is better to contain hydrochloric acid to prevent precipitation due to hydrolysis. Can be effective.

However, if the hydrochloric acid concentration rises excessively, the proportion of the platinum group element adsorbed on the ion exchange resin elutes and the platinum group is lost in the cleaning solution. Therefore, dilute hydrochloric acid is preferred as the cleaning solution, Less than 4 mol / L is preferable, and 1 mol / L or less is particularly preferable.
In addition, when hydrochloric acid is used as the cleaning solution, there is a risk of reaction between hydrochloric acid and the eluent in the next elution step, so re-washing with water to replace and remove residual hydrochloric acid on the resin surface. Is preferred.

  Furthermore, although the liquid temperature of the cleaning agent in the second step is not particularly limited, it is preferably carried out in the range of 90 ° C. or less in order to prevent the deterioration of the resin from the industrially realized normal temperature.

(4) Third step (elution step)
The third step of the present invention is an elution step in which a platinum group element is desorbed from the ion exchange resin washed in the second step using an eluent (eluent). As the eluent used, for example, an aqueous solution of thiourea can be used effectively.

When an aqueous thiourea solution is used as the eluent, thiourea has a strong and stable ability to form a complex with a platinum group element, and thus can be eluted in a wide concentration range.
The concentration of the aqueous thiourea solution is not limited. However, considering the solubility in water and the effect of elution even if it is decomposed by a slight amount of acid remaining in the resin, and considering the economy, it is 2.5 to 10%. The concentration is preferably about wt%.

  In addition, although the elution temperature in the third step can be performed at room temperature, the resin elution reaction is diffusion-controlled, and the higher the temperature, the faster the elution occurs. Is desirable. However, when the temperature exceeds 90 ° C., deterioration of the resin is promoted and the possibility of decomposition increases, so the liquid temperature in the elution step is preferably in the range of 60 to 90 ° C.

  Furthermore, in the third step, when the eluent is passed through a resin-filled column, a concentrated liquid containing a platinum group element is obtained at the beginning of the outflow, and then the concentration of the platinum group element rapidly decreases. , Mg / L order liquid will flow out for a while. If this latter half of the solution is used as the next eluent, an economical and high concentration eluent can be obtained.

For elements that are not sufficiently eluted with thiourea, such as iridium, the recovery rate can be further increased by additional elution with hydrochloric acid.
Among the adsorbed elements, some metal complexes have changed to hydroxides and polymers in the resin, and these are difficult to elute with thiourea, but the hydroxides and polymers are decomposed by hydrochloric acid, and A new chloro complex is formed. The higher the concentration of hydrochloric acid, the easier it is to form a chloro complex, and the chloro complex is more likely to be present in the aqueous solution than adsorbed to the resin, so that the elution rate can be increased.

Therefore, it is desirable to use 2 mol / L or more hydrochloric acid.
Also, if hydrochloric acid is used immediately after elution of thiourea, both will mix and some thiourea will decompose, so it is desirable to use hydrochloric acid after washing the resin with water.

Examples of the present invention and comparative examples will be described below, but the present invention is not limited to these examples.
The metal ions were analyzed quantitatively by ICP emission spectrometry and ICP mass spectrometry.

The following three adsorbents were subjected to an adsorption isotherm test for platinum element.
Adsorbent I: Amine-containing hydrophilic resin.
Specifically, a base resin produced by mixing an ethylene-vinyl alcohol copolymer and a vinyl alcohol polymer in a ratio of 8: 1, heating and melting, and chemically bonding with diethylenetriamine is produced. It has been done.
Adsorbent II: Amine-containing polymer alloy.
Specifically, an ethylene-vinyl alcohol copolymer having an ethylene content of 44 mol% and a polyallylamine having a weight average molecular weight of 15000 were prepared so as to have an N grade of 6.2%, and were manufactured by heating and melting. A polymer containing an amino group is polymerized with another polymer.
Adsorbent III: Commercially available polyamine type anion exchange resin.
Specifically, it is Purolite A-830W manufactured by Sumitomo Chemical Co., Ltd.

Adsorbents I, II, and III are each screened for particles having a particle size of 400 to 700 μm using a sieve before use, and 100 g of the sorted resin is treated with 1 L of 2 mol / L hydrochloric acid. The functional group at the end of the resin was made to be Cl-type, and after the washing, pretreatment was performed such as dehydration by suction filtration.
Further, as the test stock solution, an aqueous solution having the composition shown in Table 1 in which 80 g / L of hydrogen chloride was dissolved was used. The total chlorine concentration of this aqueous solution was 132 g / L.

  Next, as a specific procedure of the adsorption isotherm test, first, sodium chlorite was added to the stock solution to adjust the oxidation-reduction potential to 1012 mV (silver / silver chloride electrode standard, the same applies hereinafter). . Any of the pretreated adsorbents I to III was added to the liquid after the adjustment, and the mixture was stirred and mixed at 25 ° C. for 1 hour. During the mixing, the oxidation-reduction potential was maintained at 945 to 1014 mV. The mixing ratio of the adsorbent and the stock solution at this time is shown in Table 2 for each adsorbent.

After the adsorption treatment, the resin was separated by suction filtration, the platinum element concentration in the filtrate (post-adsorption liquid) was analyzed, and the separated resin was washed with water, and the platinum element quality of the resin was also analyzed.
The results of platinum element analysis of these post-adsorption liquid and post-adsorption resin are shown as adsorption isotherms in FIG.
It can be seen that the amine-containing hydrophilic resin (adsorbent I) used in the present invention has a higher adsorption capacity than amine-containing polymer alloys and commercially available polyamine type anion exchange resins.

(1) Adsorbent As an adsorbent, a base resin produced by mixing an ethylene-vinyl alcohol copolymer and a vinyl alcohol polymer in a ratio of 9: 1, heating and melting, is chemically combined with diethylenetriamine. An amine-containing hydrophilic resin produced by bonding was used.
Before use, particles having a particle size of 400 to 700 μm are sorted using a sieve, and 100 g of the sorted resin is treated with 1 L of 2 mol / L hydrochloric acid to make the functional group at the end of the resin Cl-type, and washed with water. Thereafter, a Cl-type amine-containing hydrophilic resin dehydrated by suction filtration was prepared.

(2) Adsorption process 100 ml of an aqueous solution having the composition shown in Table 1 and a chloride ion concentration of 132 g / L and a hydrochloric acid concentration of 80 g / L was used as a stock solution.
First, after adding sodium chlorite to the stock solution to adjust the oxidation-reduction potential to 1011 mV (silver / silver chloride electrode standard, the same applies hereinafter), the Cl-type amine-containing hydrophilic resin prepared in (1) above 10 g (dry weight) was added and mixed with stirring at 25 ° C. for 1 hour. During the mixing, the oxidation-reduction potential was maintained at 945 to 1014 mV.
After the adsorption treatment, the resin was separated by suction filtration, and component analysis of the filtrate (liquid after adsorption) was performed.

(3) Washing step After the adsorption treatment resin collected in the step (2) and 100 ml of 1 mol / L hydrochloric acid are mixed with stirring for 10 minutes at 25 ° C., suction filtration is performed to filter the resin and the acid after adsorption. The washing solution was separated and the components of the filtrate (post-adsorption pickling solution) were analyzed.
The resin after washing with hydrochloric acid was further mixed with 100 ml of deionized water with stirring for 10 minutes, and the resin was separated and collected from the filtrate by suction filtration, and the component analysis of the separated filtrate (water washing before elution) was performed. .

(4) Elution step The washed resin collected in the step (3) and a 2.5% thiourea aqueous solution were mixed, heated to 80 ° C., and stirred for 1 hour.
The mixture was subjected to suction filtration to separate the resin and subjected to component analysis of the filtrate (eluent recovery (80 ° C.) solution).

Further, the resin after elution was washed with 100 ml of water at 25 ° C. in a filter by the water spray method and sucked and dehydrated. The resin was stirred and mixed for 10 minutes after adding 100 ml of water at 25 ° C., and the mixture was sucked. It filtered, and it wash | cleaned by wash | cleaning and attracting | sucking again with 50 ml of water of 25 degreeC in a filter. The respective water washes were combined, and the components were analyzed as water washes after elution.
The resin after washing with water was mixed with 100 ml of hydrochloric acid having a concentration of 2 mol / L while stirring for 10 minutes, the water inside the resin was replaced with hydrochloric acid, and component analysis of the acid replacement solution obtained after suction filtration was performed.

The above-described adsorption-elution steps (2) to (4) were defined as one cycle, and this cycle was repeated a total of 4 times.
Moreover, the weight of the element contained was calculated | required from the analytical value of the aqueous solution generate | occur | produced in each process of each cycle, and the ratio (distribution:%) with respect to the element weight which exists in 100 ml of stock solutions of Table 1 was calculated | required.
The results are shown in FIGS.
2 to 15, “A” is the post-adsorption liquid, “B” is the post-adsorption pickling liquid, “C” is the pre-elution water washing liquid, “D” is the elution recovery liquid (80 ° C.), and “E”. Is the washing solution after elution, and “F” is the acid replacement solution.

  For Pt and Pd that are well adsorbed and eluted even with conventional anion exchange resins, as shown in FIG. 2 (Pt) and FIG. 3 (Pd), 80% of each cycle is added to the elution recovery solution of “D”. Pt and Pd are recovered at a distribution ratio exceeding 1, and by the method of the present invention using an amine-containing hydrophilic resin, adsorption and elution can be performed without any problem and with good reproducibility.

On the other hand, Ir, which was particularly difficult to elute when a conventional anion resin was used, was also 60% by using a method in which hydrochloric acid elution (substitution) was used after elution of thiourea as shown in FIG. We were able to recover soon.
As shown in FIGS. 5 and 6, about 50 to 60% of Ru and Rh could be recovered with only thiourea, which is equivalent to the case of using a conventional anion exchange resin.
As shown in FIG. 7, Au could recover 70-80% with thiourea alone.

On the other hand, the impurities are as follows.
Although Pb whose distribution is shown in FIG. 8 was temporarily adsorbed, 75% or more was finally recovered out of the resin.

  In the case of Bi, which shows distribution in FIG. 13, the adsorption rate decreased and the elution rate improved each time, and 75% was recovered out of the resin in the fourth cycle.

  As shown in FIG. 9, adsorption of Sb was suppressed, and 80% or more could be separated from PGM after the second cycle.

  In the method using a conventional anion exchange resin, Sn having a distribution shown in FIG. 11 behaves like Sb and accumulates in the resin. However, in the method of the present invention, almost 100% can be separated and recovered from PGM. It was.

  As shown in FIG. 10, FIG. 12, FIG. 14, and FIG. 15, As, Te, Se, and Cu hardly adsorbed themselves and could be selectively separated from the platinum group elements.

  As described above, from the platinum group aqueous solution containing Cu, Se, As, and Te as impurities shown in Table 1, the platinum group element and main matrix components are obtained by the method of the present invention using an amine-containing hydrophilic resin. It was confirmed that they could be separated sharply and that the adsorbed platinum group could be efficiently eluted and recovered from the resin.

Moreover, even if it used repeatedly, it has confirmed that the adsorption rate and collection | recovery rate of a platinum group were maintained high.
Table 3 shows the recovery rate of valuable metals compared to Example 2 and the invention of Patent Document 3 (conventional example).
According to Table 3, it is clear that platinum group elements can be recovered at a higher recovery rate than before.
It is also clear that gold can be recovered at a higher recovery rate than before. Since the adsorption rate was high, the recovery rate could be increased.

Claims (6)

A method of recovering the platinum group elements from acidic solutions containing at least platinum or ruthenium platinum group element and impurity elements,
A method for separating and recovering a platinum group element, wherein the following steps (1) to (3) are sequentially performed.
(Record)
(1) Adsorption treatment in which the acidic solution is brought into contact with water-insoluble resin having a structure in which an amino group-containing polymer is chemically bonded to a hydrophilic polymer, and the platinum group element contained in the acidic solution is adsorbed on the resin. The first step to do.
(2) A second step of cleaning the resin that has adsorbed the platinum group element through the first step.
(3) A third step in which an aqueous solution containing thiourea having a liquid temperature of 60 to 90 ° C. is brought into contact with the resin having undergone the second step, and the platinum group element adsorbed on the resin is eluted.   2. The platinum group element according to claim 1, wherein the acidic solution in the first step is maintained at a potential of 700 to 1100 mV as an oxidation-reduction potential using a silver / silver chloride electrode as a reference (reference) electrode. Separation and recovery method.   The cleaning process in the second step is a process of cleaning the resin by sequentially bringing a hydrochloric acid solution and water into contact with the resin after the adsorption process. Separation and recovery method.   The method for separating and recovering platinum group elements according to claim 3, wherein the hydrochloric acid solution has a chlorine ion concentration of less than 4 mol / L.   The elution treatment in the third step is characterized in that, after bringing the washed resin into contact with an aqueous solution containing thiourea, hydrochloric acid having a concentration of 2 mol / L or more is brought into contact with the resin. 5. The method for separating and recovering a platinum group element according to any one of 1 to 4. The acidic solution is
Platinum, and at least one platinum group element selected from the group consisting of Le ruthenium,
6. It is composed of a hydrochloric acid acidic or chloride solution containing at least one impurity element selected from copper, nickel, gold, silver, selenium, tellurium, bismuth, antimony and arsenic. The method for separating and recovering a platinum group element according to any one of the above items.

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